竞赛配置子赛项

app/views/settings/show.json.jbuilder

@@ -67,7 +67,5 @@ json.setting do
     json.system_notification nil
   end
 
-  json.sub_competitions do
-    json.array! EduSetting.get("sub_competitions")
-  end
+  json.sub_competitions EduSetting.get("sub_competitions")
 end